/Engine/Source/Runtime/RenderCore/Public/RendererInterface.h
X, Y Position in screen pixels of the top left corner of the quad SizeX, SizeY Size in screen pixels of the quad U, V Position in texels of the top left corner of the quad's UV's SizeU, SizeV Size in texels of the quad's UV's TargetSizeX, TargetSizeY Size in screen pixels of the target surface TextureSize Size in texels of the source texture VertexShader The vertex shader used for rendering Flags see EDrawRectangleFlags
void DrawRectangle ( [FRHICommandList](API\Runtime\RHI\FRHICommandList) & RHICmdList, float X, float Y, float SizeX, float SizeY, float U, float V, float SizeU, float SizeV, FIntPoint TargetSize, FIntPoint TextureSize, const [TShaderRefBase](API\Runtime\RenderCore\TShaderRefBase)< [FShader](API\Runtime\RenderCore\FShader), [FShaderMapPointerTable](API\Runtime\RenderCore\FShaderMapPointerTable) > & VertexShader, EDrawRectangleFlags Flags )